Spinning method and apparatus



y 1952 B. LIEBOWITZ Q 2,602,195

SPINNING METHOD AND APPARATUS Filed April 9, 1948 5 Sheets-Sheet lINVENTOR, flaw/WW L/zaow/rz ATTOIP/VEVS July 8, 1952 B. LIEBOWITZ2,602,195 SPINNING METHOD AND APPARATUS Filed April 9. 1948 5Sheets-Sheet 2 y 8, 1952 B. LIEBOWITZ 2,602,195

SPINNING METHOD AND APPARATUS Filed April 9, 1948 -5 shee'ts sheet 5 iLEG i INVENTOR.

July 8, 1952 B, UE OWZ $602,195

SPINNING METHOD AND APPARATUS Filed April 9, 1948 5 Sheets-Sheet 4 '71 Qmy 4 INVENTOR. fif/X/fl/W/V 0550/4072 H44 v K Q/W y 8, 1952 B. LIEBOWITZ2,602,195

SPINNING METHOD AND APPARATUS Filed April 9, 1948 s Sheets-Sheet 5 E U Ya small amount of draft to a much longer draft previously produced inthe conventional manner.

When simultaneous draft and twist is imposed, as in the mule, or as inthe German proposal, the advantage claimed is that those portions of theroving which are relatively thin will take more twist and hence lessdraft. American spinners have claimed that this advantage does notproduce any appreciable improvement in the yarn except possibly forexceedingly fine yarns. My experiments support this latter view as willbe described below.

When simultaneous twisting and drafting is.

imposed, as in my system, however, my experiments show that I doproduce. a smoother and more uniform yarn. The reasons for thiswillposed by the breaker-draft rolls I lAB is only a matter of a fewpercent; in fact, the main function of using two sets of rolls, H! andH, for feeding purposes is to insure more uniform feed without employingexcessive pressures. The system of rolls WA and B, HA and B, willhereafter he collectively referred to as the feed roll system or as thefeed roll means. Under suitable conditions they may comprise only asingle pair of rolls instead of two pairs as shown in Fig. 1.

From the feed roll system the roving 20 passes to the hyperboloidal longdraft rolls l2A-|2B.

be discussed in connection with Figs. and 6 below.

My invention will be more fully understood by reference to theaccompanying drawings, in which 7 Fig. 1 shows a diagrammatic sideelevation of the essential parts of a spinning frame employinghyperboloidal rolls as the main drafting rolls according to myinvention; V

Fig. 2 is a plan view corresponding to- Hg, 1;

Fig. 3 is a diagrammatic side elevation of a spinning frame employinghyperboloidal rolls as the main drafting rolls, in which a belt systemis employed in a manner which is well known in the spinning art today;

Fig. 4 is a plan view corresponding to Fig. 8;

Fig. 5 is a diagrammatic plan view showing the effect on the roving ofthe, process employed in mule spinning or in the German disclosurereferred to;

Fig. 6 is a plan view showing diagrammatically the effect on the rovingof the hyperboloids as employed according to my invention;

Fig. '7 is a diagrammatic side elevation showing the essential parts ofa spinning frame employing hyperboloids both as feed rolls and asdrafting rolls according to my invention;

Fig. 7A is similar to Fig. 7, showing a modification thereof comprisinga friction drag between the feed rolls and the drafting rolls;

Fig. 8 is a plan view corresponding to Fig. 7

Fig. 9 is a plan view in the direction of the arrow IX of Fig. 10showing diagrammatically the application of hyperboloids both as draftrolls and feed rolls to a spinning frame;

Fig. 10 is a side elevation of the apparatus shown in Fig. 9, theapparatus being shown partly in section on the line iillfl of Fig. 9;

Figs. 11 and 12 are similar to Figs. 9 and 10 respectively and show analternative embodiment,

Fig. 12 being taken on the line l2-l2 of Fig. 11;

Fig. 13 is a pianview showing a portion of the apparatus of Fig. 9 asmodified by the provision of a positive drive for the upper feed rollsand for the upper draft. rolls;

Fig. 14 is a front elevation detail view showing one of the mating pairsofhyperboloidal rolls of Fig. 13 and the gearing a'ssociated'therewith;

Fig. 15 is a detail section on the lin i5l5 of Fig. 13, and f Fig. 16 isa plan view showing a portion of the apparatus of Fig. 11 as modified bythe provision of a positive drive for the upper feed rolls and for theupper draft rolls.

Referring to the drawings, 13A and [8B representv a pair of feed rollsas employed in conventional frames. HA and HB represent a pair ofso-called breaker-draft rolls also as employed in conventional frames.The amount of draft-im- In modern systems the drafting rolls impart longdrafts of the order of 10 to 20, or even more. In my system I impose thesame order of magnitude of draft by the drafting rolls l2A-l2B. Butinstead of being cylindrical in form the draft rolls are hyperboloidalwith axes making an angle with each other. Hyperboloidal surfaces areused in my system because they have the property of having line contact.If cylindrical rolls were employed with non-parallel shafts, the contactbetween the roll surfaces would only be at a flattened point instead ofalong a line and hence would not be suitable for the purposes hereintended. Of course, it is not necessary that the surfaces employed beaccurately hyperboloidal, in a mathematical sense, but only that theyshall be hyperboloidal within the accuracy required for the purposesintended. The action of these hyperboloidal rollers is to roll theroving while drafting it, thereby imparting simultaneous draft andtwist. However, it must be understood that the twist imposed is only afalse twist or .nonconservative twist. For example, in Fig. 1 the effectof the hyperboloidal rollers l2Al2B is to impart a twist to the stretchof roving 20A between the nip of the hyperbclcids and the nip of thebreaker-draft rolls HA-B. The roving issuing from the hyperboloidstoward the eye E3 of the spindle will have no twist, except insofar astwist is imparted by the spindle I4.

From the eye 13 the roving passes as usual to the traveler l5 and thenceto the spindle l4 whose rotation serves to subject the roving to truespinning in the well-known manner in order to impart permanent twist.The. permanent twist thus imparted ordinarily is in the same directionas the false or non-conservative twist imparted by the hyperboloids andserves to conserve at least in part the non-conservative twist.

In modern American drafting frames, it is customary to use some sort ofbelt arrangement to support the roving as it passes from thebreakerdraft rolls l |AB to the drafting rolls. The same sort ofsystemcan be employed when the drafting rolls are hyperboloidal, as isshown in Fig. 3, in'which I? is a thin fiat belt which is driven by thebreaker-draft roller HB, and. passes over pulleys I8 and is. Directlyover the roller !8 is an auxiliary roller 21 which rests on the rovingwhich in turn is supported by the upper stretch of the belt 17. Theadvantages accruing from the use of such belting arrangements are wellknown, among which may be mentioned the ad vantage of not requiringadjustment for small variations in fiber length. Instead of the beltarrangement, I may employ a frictional drag 128 as shown in Fig. 7A. Toguide the roving to the drag, I may employ a guiding element i2! whichpreferably does not touch the frictional drag I26.

However, the use of belts or drags is not essen-- trial in the practiceof my invention.

least of the-order of 4-to-1 orthereabouts.

7 drical, rolls. Again, thev fact that the roving emerges from thehyperboloids in the form of a smallapproximately cylindrical rod,instead of in the form of a relatively wide tenuous ribbon as inconventional systems, also helps the propagation of spindle twist to thenip of the roving and again reduces the tendency of the yarn to break atthis point; These improvements in twist propagation allow the use ofhigher speeds. Thus the advantages accruing from the use of lon drafthyperboloidal rolls comprise greater uniformity of yarn, greatersmoothness of yarn, less tendency forthe yarn to break both in thedraftingpart and inJthe true spinning part, hence less attention, alsohigher speeds, and finally, lower costs. ,Furthermore, I have found thatI can obtain very satisfactory yarns using rovings of materially shorterfiber length than is customary for the type of yarn involved. Thisconstitutes one of the most importantsavings introduced by my system ofhyperboloidal spinning.

In this specification I have described the distance between the nip ofthe draft rolls and the nip of the feed rolls as being of the order of afew fibers in length. lhe expression "a few fiber lengths as used hereinand in the claims is intended to mean anything from a little more thanunity to, roughly, 3 or thereabouts, and is not to be restricted tointeger values, but may be any integer or any fraction in thatneighborhood. The fiber length referred to is that determined bystandard procedure. It is not feasible to define the length of thestretch between the nip of the draft rolls and the nearest nip of thefeed roll system more precisely than this for reasons which are apparentfrom the following data respecting certain of my experiments which areillustrative of the practice of my invention in connection with thedrafting of cotton roving, the nip distance referred being the length ofthe stretch between the nip of the hyperboloidal drafting rolls and thenearest nip of the feed roll system.

In some of these experiments I have drafted successfully roving whosefiber length is 1 /8 using a nip distance of about 2", and using thesame nip distance I have also drafted roving successfully whose fiberlength is 11- 1;". In still other experimentsI have used a nip distanceof around 2 /2" with fiber lengths in the neighborhood of li i and haveobtained successful results. but found it necessary in order to obtaingood uniformity to employ a frictional drag asshown in Fig. 7A. It willbe seen in connection with these experiments that I have used ratios ofnip distance to fiber lengths varying from about 1.25 or "1.3 up .toaround 2 In any case, the expression a few fiber lengths.

as defined and illustrated above covers a bracket ofnip distances whichis entirely different from the distances of many fiber lengthsemployedin mule spinning and. proposed in mule substitutes.

Mysystem'differs from previous systems employing combined drafting andtwisting not only Withrespect-to the roller nip distance but alsowithrrespect to the amount of drafting. Previous systems '(i. e., themule or the mule substitutes) employonly very small drafts of the orderof a few percent or perhaps 25 or 30% or in that neighborhood; while inmy system I employ long draft, bywhich I mean, in cotton, something atOf course, in drafting other fibers, e. g., wool, the term long draft isto be construed as, low as 2-to-l or .thereabouts, because such fibersare habitually drafted to a much less extent than cotton fibers. On theother hand, in drafting" synthetic fibers long draft again isto beinterpreted as having a meaning very much the same as for cotton. Withregard to fibers such as jute fibers are not well suited for beinghandled in the practice of my invention unless they are artifiv ciallyshortened. In actual practice, in drafting cotton fibers of ordinarystaple length, my invention contemplates obtaining drafts of 10-to-l andpreferably more; and in practice I have succeeded in obtaining drafts of20-to-1 and more in cotton roving whose staple length is of the order of11%". I have also successfully obtained drafts of the order of 20-to-1using synthetic fibers, e. g., a mixture of 1 acetate fiber and 1%viscose fiber. I have notdetermined the upper limit of draftingobtainable by my method, but I have found that the .usual rule of thumbaccording to which the draft shall not exceed one fold for each fiberlength, does not apply to my system, because I can use substantiallygreater drafts than specified by this rule of thumb.

Other quantitative conditions which have been mentioned above, forexample, the setting of the hyperboloidal rolls at a 12 angle, arelikewise to be considered as illustrative rather than as definitive. 1 I

The amount of false or non-conservative twist imparted to the roving bythe action of the hyperboloids is dependent upon the hyperboloidal angleX of Fig. 6. As soon as the hyperboloidal angle X is prescribed, thehelical angle of twist is also prescribed, and from the helical angle oftwist the number of turnsper inch can be calculated by the followingformula:

Number of turns per inchztan X+21rr where T is the radius of the rovingbeing twisted. When the hyperboloidal angle X is 12", for example, itfollows that the tangent of 12 is 0.212. Also by way of example, if theyarn being twisted has a diameter of 0.003 inch, then the number ofturns per inch imparted to the roving by the pair of hyperboloidal rollsequals As the formula indicates, increasing the size of the roving willdecrease the number of turns per inch in proportion, and vice versa. Thetwist imparted by a pair of hyperboloidal rolls whose hyperboloidalangle is 12 corresponds roughly with normal fully twisted yarn. It willbe recognized that the twist imparted by a pair of hyperboloidal rollswhose hyperboloidal angle is 12 is such that the roving could not besubstantially drafted if the twist were to be propagated sub stantiallyuniformly from the nip between the hyperboloidal draft rolls to thenearest nip of the feed roll system. However, by virtue of the fact thatin the practice of this invention the long draft imposed by thehyperboloidal draft,

rolls prevents propagation of the twist created by said rolls beyond ashort distance from the nip of said rolls, the roving becomes locallyattenuated so that most of the twist becomes concentrated in theattenuated region immediately adjacent the hyperboloidal draft rolls andthe portion of the stretch merging with this region contains less twistwhich permits long drafting of the fibers as they are drawn into themore highly twisted region adjacent the nip of the hyper boloidal rollswhere no substantial drafting of the fibers occurs. At the same time, byrestricting the distance from the nip of the hyperboloids to thenearestnip of the feed rollsystem to a 'few feedroll'-systems-, Imayemploy hyperboloidahrolls for-"the feedrolls-as-well -as.the draftrolls, as. shown in*Fig-s. '7 and" 8. Here the-hyperboloidal rolis'3Aj-and= 23B take-theplace-of thenbreaker-l dr-aft rollers- I I A I LBor may beused :just .by themselves i for the feeclrollsystem. "The strumtural a =dva-nta-ges gained by employing :hyperboe loidal feed rollsinthis-way will. become manifest fromFigs-. -9 and 10.

-'-I-n"order to understand more clear-1y; theiaction ofthehyperboloidahrolls. as used incmy; system to produce a combinationoflongldraftiandtwiste ing simultaneously, 1 I have. shown .diag-rammatie. callyin Fig-A6 the ac-tion of .the..shyperboloidal rolls-on thestretch of rovinglOA between the feed or breakeredraft rolls H and the".hyperboloidal draftrolls l2. Itwill' be -seen that close .to the, nipof the hyperboloidali rollsstherexisie gregion Kfhfi he roving-which is.highly? twisted. This region is--comparativelyshort. LIn.itz-noedraiti-ng takes place. Next tol the. region K regiOnL whi ehisthe transition region in which: combined drafting and-twisting takesplace, the amount. of; twist b'eing relatively. small .whilethe. amountof the draftis large.

rolls I l: in-whichthereisnoztwist (except that initially in the roving)and apparently very little, any, draft. .I'I hesumbf the lengths; K, L,

denoted by:P,;is.of.the. orderof ,a few fibers,

It will be Y in -length, more ordess (see below )v understoodthatthatransition from regionK to regionL-is gradual, not. sharp, and likewisefrom region L-to'M. Thelines of demarcationbetween these regions are,therefore, drawn somewhat arbitrarily but they serve. to. showtheexistence of thethree zonesKL M, and toindieateroughly theirrespective extents.

In contrast.with.the situation shown i Fig; 6,;1 show iin. Fig. hthecorresponding state ofafiairs obtainingin' the mule: or in themule-substitute shown in .the' German disclosure referred to above.Herea feed rollsystemis indicated; by the reference character ll. H theroving passes to the cylindrical drafting roll-pair D which impartsnearly allthe draft the roving is to receive, butno twist. The rovingthen passes toa pairiof hyperboloidal rolls'l'H (intheGermandisclosure). or to a .travelingspin'dle (in the. mule) The stret'ch ofroving between Dand H is many fibersin lenth,.and, as shownflissubstantially" Dair" 'D..is on1y.somewhat more than a'iiber in' length,unless albeit system is used, in which case it maybe somewhat longer.In'the region'Q the'amount'of twist. andthe amount of draft are bothsmall.

"The basic difference between myuse of the hyperboloidal rolls and theprevious, proposals willbeclear from Figs. 5 and 6. It will beunderstoodthat in Fig. ,5, which we may call .mule type spinning nodraft can take place in the short regions between the nip of the draftrolls D and the twisted p'artof the roving, since this'distance Sfisgenerally substantially .less than a fiber in length; the drafting'duetothehyperboloids' or spindle to 'the extent'that it exists at all; is inthe "long-twisted stretch T'-,Q-"S. Attempts which I have madeto obtainlong drafts with an arrangement corresponding'to Fig; 5have shown thatthere-is an; instability-between drafting and twisting-in the sense:that if "long; draftis' "imposed the twisti's not propagated back alongthe" Mis the region of theroving, nearest to -the-nip of. the feed.orsbreaker draft 6. stretch; of.:r.oving Q, :except for. -;a shorttwisted portion-near the hyperboloids; almost the. entire lonereg-ion Q.is thereioregsubjectrto draft and; having no 'twist, emergeshighlynon=uniform and. -subject ,to frequent breakage. If, however,onlyzsinallodrafts are. imposed and, only. a modem. ate amount? of:twist,-. then, it. is: possibleio; obtain, y,..3 0.%draft inthe mannershown inFig; 5,:but my.=.-experimen ts have actually shown-that: so :farasayarns ofgordinary sizeyare concerned, say up.

to 49s ;or "508, thereis no. improvement the qualityiof; theyarnobtainedby using hyperbo-l'oids in this, way.- i. -.e.. as: anauxiliary-toe modern long draft: system. If, however,: a relatively high;-degree. o twist .-is..-imposed, i. e.,; if the; anglesof thes.hyperboloids shownat X ,in'Fig. 6: are fairly large;enemy-experiments12. degrees), and if 'the stretch Bof' Fig. '6- is. suitablychosen,'.then ,long draft: and high twistrcanzbe simultaneously .im-..:Desed with; the. part ofuthe roving subject to draft and twist takingthe form. shown diagrammaticalily in Fig-o6. Under. these-conditions, i.e., .:wi th relatively .large .angles X, with relative short stretclrP,and'with, long draft imposedgthewre sulzting yarn is very .uniiorm and;notisubject to frequentbreakage.

At. the same time, my system as. illustrated in Fig. 6; difiers.radically in its action; from ordinary systems. employing cylindric a1:draft rolls. In the izconven-tional system only: those fibers are drawnout whicharenippedby the draftrolls. "'Inmy. system, however, the.fibers whichsare drawn out are not only-those thatare nippedby-thehyperboloidsbut. also those-which are caught inthe ghigh-lytwisted region K. 'Infact; injthe:practice of myinvention thelengthof:the stretch-of roving that isbeing drafted is so restricted: thatsubstantially those fibers. only .are drafted-iwhose ends have becomeentrained. in the. highly v twisted region K. Now, a thinner .portionofthe roving comes along itswill'begin to experience this'high' twistearlier in its .travel and ihencew-ill. tend to pull out-morefibersfromthe roving .following it. Onthe other .hand, ifa thickportioncomesalong it will become-subjectto high twist later .in its travehandhence. will draw outsless' fibers'irom the rovingfollowingrit. In thiswaya-my' system acts to even out irregularities theroving and therebyhelps-to produce a more uniformzyarn than the conventional-system..Moreover, ,the rolling action of the hyperboloids tends to pro,-. ducea smoother. yarnlwith less hairinessso that the resulting. yarn looksmuch like acombedyarn even when the roving .itself isnot; combed; Eurthermore, because of the strength imparted-to the roving in the region Kandinthelcwer.partzof the region L there, isless tendency for the,roving to. break. It is preferable that thetwist imparted by thehyperboloidsin the zonal and .K. shall be. in.=.the same direction asthe twist;.initially..in;the roving and also in the same .directionas.the-.final true twist imparted by thesplndle. ,Havingthe initial twist 1the, roving. inthe same; direction asthatimparted by the hyperholoids;vlqlpsto pro: ;duce.more uniform yarn. Thehighly twistedino ition. K?after passing; through the .hynerbploids. has. no'twist. .(except; the.attenuated residuumpf twist initially in the roving). but. having; once.been twisted,v it acceptsthe twist imparted .by th spindlemore readily.Thismeansflthat-the break; as. .it emerges. from .the. .:.draftingrolls: as compared with nonventionai.v systemsi using. cyline.

"9 zfibersc-inlength, the zone of drafting is confined toastretch ofroving not greatly in excess of one :fiberclength. My experimen'tshavedemonstrated rthatthis'restriction on the drafting zone is essential-foruniformity. While .a hyperboloidal angle .of -l2 .for thehyperboloidaldraft ,rolls' has been .found toafford highly satisfactory results inthe spinning of cotton yarnvfrom roving, other angles may be used .forimparting-either a gloat/er or .lesser non-conservative twist asmay'bedesired. However, .it .is contemplated in the practice of thisinventionthat the feed roll systemanddraft- .ingrolls shall .beopera'tively arranged so that a longdraft will be accomphshed'acrossastretch ,limited to' .a few .fibers in length while simultaneously roll.tw'istingithe roving in the immediate neighborhood of the .nip between.thewdraftting .rolls sufficiently to substantially prevent draiztin'gof .lthe-cfiberslin thisregion while-drawing the fibersointo this.regionfrom the portion of I wstretchrm'ore adj acent'the feed rollsystem wherein diminishing twist permits the'long. draft tO'hGaccomplished. .In other words, any such nonconservative twisting oftheroving createsa fhigh twist .and at the .same time, according [to,this invention, .a long-'fdraftis alsocreated as thefihers are drawninto .alocaliZed ,region of the ,high twist. .The magnitudeof,'the..draft servesto confinethe. high; t'w'istito thereg'ion,immediately ,ad-

jacentitheo draft roll nipand to confine the draft --within said;limitedstriatdhasthe rovingiis passed through the system.

The problemof driving hyperboloidal: rolls. in a drafting; frame is by.no means simple ,whenlap- ,proached. along.conventionallines. The,multiplicity of skew-gears which fwolildprdinarily Joe involved becauseOftheanglesmade bythehy- I perboloidal .axes represent not only aburdensome addition .to. first .costi.but,also addedmaintenance andoperating costs and complications. .MQreover, the problem of supportingthehyperboljoids in. such .a way as toputpthe pressure in a.welldefined-manner on the. roving andnot, partly ,on the. ro'vingandpartly .ontherolls. is, not.,easy of simple. solution; when approached.in conventional .manner. .Ihaveovercomeall of.. these.and other.difficulties inca simple and. efiicient .-;ma nner,..by (1) employing.hyperboloidal: feed. rolls as :well: as thyperboloidal draftingrolls(the two..sets of,rolls having the sameangle) (2) by. assembling .oneroll of one .pair-ltoa corresponding roll {of ca neighbo'ring pair one.common. shaft in idumb- LbelI fashion, and(3) .by mountingthefitfil'feispondihg" mating... hyperboloids on separate "adjacentparallel shafts. "'I'hisarrangement, ermits of the 'use'of longstraightishafts runningthe length of the'frame, in amanner-corresponding to that employed in conventional spinningframes,and of associating hyperboloids with these shafts in such a manner as torequirerno gearing other t-han employee-an thyeridsoftheshafts as ,in

"conventional'spinning frames. so far as the'driving-arrangement isconcerned; the only difference between nay-- system and the-conventiona1 system 'is that I employ two longitudinal shafts "where-the* conventional system employs only. one. "On the other hand iii-viewof the improved feeding 1 characteristics of t'hehyperboloid'al feedrolls, it is not essentiar that I- use'both feed rolls and breaker-'draft rhlls,although I'may use this combin'ation if I'-'choose. "Bydispensing'with one pair of rolls of the feed rollsystem; I requireonlyflfour 'shafts,"-whichis" a trivial disadvantage :With re- "spect tothe "three, shafts. employed in convent tional'frames.

10 All of this will be more clearly understood by referencetoFigs. 9 and11), in which 4| is a base member carried by the spinning frame in anyconvenient or conventional manner. Mounted on this base 4| isasuccession of brackets 42 in which are mounted hearings forthe fourshafts 43, 44 45 and 46. 'Ijheseshaftsmay be restrained a ainst endwisemovement by washers or collars 4l. .At

.the one end of shaft 43 1s a gear 43, likewise 44 hasgearAS, 4j5jhasgear it, and 46 has gear-5 l. Mating with both gears 48 and :9 is a gear52 on driving shaft "53. Likewise mating withgearsfijl andcfi'l is'agear 54 which is driven by a conventional system of change gears fromthe shaft .53. Bvlcno ceo sear inith han eveea system, the'relativespeed betweenshafts 43 -44 on the one hand and 45-46 on theother handis ,controlledso asto determine the amount of draftimposed'byth system- A Set o f ru pe hvvpertclloiolal fee rolls is sh wna ;55 EBA-1 1A .a'ndEBA. jLikewise a corresponding set ot-four .lower,hynerholoidal gfeed rolls is indicatedat 55B,

5 613,513 and 583. Similarly, a set of four upper ,hyperboloidaldrafting rolls is shown at 59A; 'BQA, .615 and ZEZA, and acorrespondingset of lower hyperboloidaldrafting rolls isindicated atEQB,

60B,.6l-B and 152B. The manner in which the hyperboloidal rolls aredisposed in pairs is clear from Fig. 9. A braceofptwoneighboring upperfeed rolls 55A and 56A is mounted on a common shaft whose end is shownat-63. The shaft 63 passesthrough a smallX-casting t? which serves feedrolls 5 lA -and STE-are associated on a common shaft- 54. Likewise, theneighboring upper 'hyperboloidal draft rolls 5 9A-and BEA are associatedon ;a common shaft -65,-while neighboring upper hyperboloidal draftrolls'GlA and 62A;are associated on a common shaft 66.

The shaft 63 cornmon to the bi'ace of upper feed-rolls 55A and 5;6A is-mounted in a small X- casting 6-1. Likewise-58 denotes the X-castingwhich carries; theshaft 64,159 that which carries the shaft, and it!that which carries the shaft 66. Each o f these 'X-castings is drilledto receive ,a cylindrical rod ll-whose axis makes with the axis, ofthe'roll-shaft an angle of degrees minus the hyperb'oloidal angle shownat X in Fig.6. The rod]! which passes throughthe casting 6'! also passesthrough the casting 69 sof that these two X-castingsare also associatedinpairs. In this manner common-carriage means is provided-*for-the-groupof rolls 55A,-56A,-59A and -60A whose axes of rotation are disposedsubstantially in a common plane which is in parallel relation to theplane in which-the-ax-es of rotation of the-lower group of :rolls BEE-B,59B and 66B are disposed. Each of these castings is located-endwise onthe -rodloy means of .snap ringsor collars shown'at '12. The rodllitselfis slidably held atone end in a vertical groovei'l3 in post 'l l whilethe other end is similarly constrained by;-groove 15 in the barflfi. Thepost.

is. rigidly-mounted on the base by means ofthe bar 57 which is rigidlysupported on the brackets 42. The bar 18 islikewise rigidly attached tothe brackets 42 as by means of bolts 18. In this way the cylindrical rodH is so mounted that each end can move up and down freely, but at thesame time is restrained so that it cannot move endwise and. so that itmaintains a fixed angle with the shafts 43-44 etc. The X-castings 67 and69 which are bored to receive the rod H can rotate freely on rod H.Hence, if a load is applied vertically to the plane of the drawing ofFig. 9 to the rod H, the pressure caused by said load on the rolls 55A,56A, e. g., will be evenly distributed between them. It is thus seenthat this system of mounting accurately locates all of the upperhyperboloidal rolls in their desired positions and at the same time actsas a distributor so that the load in fixed and desired pro ortions willbe distributed among the four rollers 55A, 56A, 59A, 60A, all four saidrollers constituting a group. The load is equalized between the pairs offeed rolls 55A and 56A; likewise it is equalized between the pairs ofdrafting rolls 59A and 68A. However, the proportion of the load carriedby the feed rolls 55A and 56A on the one hand,'and that carried by thedraft rolls 59A and aflA on the other hand, is determined by the pointat which the load is applied with respect to the centers of the shafts63 and 65.

As shown in the drawings, this load may be applied by means of a bentrod 80 whose upper end may terminate in a ball 8! which rests in aslight depression on a boss 82 of the X-casting Bl. At its lower end thebent rod 80 carries a fulcrum 83 for the lever 84 pivotally attached tothe base at 85. Weights may be applied in the conventional way at theend 86 of the lever 84. It will be seen that in the scheme shown thevertical load is applied to the X-casting 61 instead of directly to therod 1 I, but this mode of applying the pressure is such as not tointerfere appreciably with the rocking motion of shaft 63 relative torod 1! and hence this mode of application of pressure is permissible. Ashere shown, the point of application of the load is closer to the shaft63 than to the shaft 65. Hence, the pressure of the hyperboloidal feedrolls 55A and 55A will be greater than on the hyperboloidal draft rolls59A-66A. 7

Corresponding to the description of the X-castings 61 and 69 and the rodH, etc., associated with the draft rolls 55A, 56A, 59A, 60A, i anidentical set associated with the rolls 51A, 58A, 6| A, 62A. Thisstructure is repeated throughout the frame. Each set of four rollsprovides for feed rolls and drafting rolls for two spindles. I have notshown any breaker-draft rolls, but it is clear that by adding anotherpair of longitudinal shafts and extending the rod H, an additional setof rolls can be handled, although it will be recognized by all competentmachine designers that this will require that one set have an additionaldegree of freedom vertically and that additional means must be providedfor applying the vertical load on the additional set of rolls. Thematter of providing an extra set of rolls for the feed roll system, i.e., providing a set of breakerdraft rolls, will be discussed presently.

Associated with each upper roll, whether it be a feed roll or a draftroll, is of necessity a lower roll on which the upper roll bears withthe pressure created by the weighting system. The problem of properlylocating and driving these lower rolls has been solved by placingalternate lower rolls on alternate shafts, as shown, i. e., the

roll 523A is carried on shaft 46.

any conventional manner. The distance between the centers of the shaftsof the pair 45-45 when divided by the distance between the gorge circlesof the hyperboloids 55A, 55A shall equal the sine of twice the angle ofthe hyperboloids as shown at X in Fig. 6, e. g., shall equal sin 2X.Once the distance between hyperboloids on a common shaft has been fixed,and the angle of the hyperboloids has been fixed, the distance betweenthe shafts of the pair 45-46 is determined. Since we have chosen to makethe angle of the hyperboloids of the feed rolls the same as that of thedraft rolls, the distance between shafts of the pair 4344 will be equalto the distance between shafts of the pair 4546.

It will be seen, then, that by this arrangement of upper pairs ofhyperboloids on a common shaft in dumbbell fashion and of correspondinglower hyperboloids on suitably-spaced separate shafts, we are able todrive the entire hyperboloidal system by a means which is no morecomplicated than the means for driving conventional cylindrical rollsexcept for the addition of one shaft.

It is true that if we include another set of feed rolls so as to obtainthe benefits of breakerdraft rolls, we would complicate the system byadding two more shafts besides adding the breaker-draft rollsthemselves. However, it is possible to obtain sufficiently uniform feedusing hyperboloidal feed rolls of properly selected materials and ofadequate diameters so that the use of the breaker-draft roll is notessential so far as obtaining uniformity of feed is concerned. Moreover, if an additional pair of hyperboloidal feed rolls is added, theregion of the roving between that pair and the next pair following it(i. e., the breaker-draft pair) will be highly twisted by the action ofthe hyperbcloids, and since the draft in the breaker-draft rolls isusually very small, this twist will be propagated all the way back tothe nip of the first pair of hyperboloidal feed rolls. It is thus seenthat any attempt to create small draft by means of breaker-draft rollswould be frustrated by the fact that the roving in this region would behighly twisted. Moreover, in conventional spinning frames thebreaker-draft per se is very small indeed, of the order of 6% in manycommercial frames. This amount of draft is trivial and the onlysignificant purpose of breaker-draft rolls is to obtain more uniformfeed.

One of the reasons why single pairs of hyperboloidal feed rolls tend togive more uniform feed than cylindrical feed rolls lies in the fact thatthe hyperboloidal feed rolls will twist the roving entering the nip, andsince there is no draft between the feed roll and the creel, the twistthus created will be propagated all the way back to the creel, asexperiment shows. The roving thus enters the feed rolls in the form,roughly, of a slender rod, and not as a fiat ribbon, so that, althoughit is to a large extent flattened by the pressure on the feed rolls, thefeed rolls nevertheless have a more uniform hold on the roving.

Returning to Figs. 9 and 10, the rest of the description will be clearto those skilled in the art. From the draft rolls the roving passes asusual to an eye I3 from the eye to the spindle mating pair.

.While -the arrangement-shown iniFigs.5.=9. and

. 10. of .associating :two-upperrieedrolls (-orzsdraitraud in reducingtoa minimum1 the number oi'i 1 parts which have .to be made.

:W'hile suitable apparatusof simple and efli'cient construction hasbeen-- shown in Figs" 9 and :10 which embodies and which is adapted .forthe .114 spinningiirame has: been-reducedsoithatzinstead1.:of:atwn:shafts IIG'iHg'TQQUiTGd don-.theilower; rolls act-twoadjacent pairs of vrollsonly;one-is required, awhile; modified-supportmeans .ofxthe pppen-rolls 5 sofezthe aadj acent :.pairs is employed.soathatathe clipper:- rolls wi11..;:mate':.- properly with :;the; lowerrolls.

"lathe.v embodiment shown in Figssl 1 ."and 12, rithe base .4 Is andthegbrackets 42; are thesame as iin::Eigs.I 9:.and. .10. -The bracketscontain: bearings r 1the=;shaftsa- -86.-.and fi'iuwhichz are -restrained:..-fr om endwise movements bythe collars 8B. eshaft 4%. is thefdrivingshaftzand: onv the endoiit is l-imounted;-thegean 89. :Thergear.Bflqonptheshaft ;.pra ctice: of my invention; the; principles 1utilized; .1 5 z: '8 I .;is: driven :Iriomthe gear :8 9.:through.ascent/enin the specific constructionsh'own and described "can beavailed'ofinbther constructions. *Gen- .nerally speaking,'thexprinciples illustrated in con nection with the specificconstruction shownean tional-ehange; gear: system such as; gears? 9 I1:and .92 .so as'ito determinelthe amount of draft-imposed lz-byithesystem.

-. A1: brace. ofv lower :hyperboloidalxzrolls 93B; and

' be availed of according to :my invention by pairinggeowfiAB-dsamountedon shaft 87 .in. .spacedrelationfor adjacent hyperbol'oidal roll-pairsof likefunc- 1 tion (e. g.; two pairs of feed rolls) in sets-so thateach set comprises four rolls two like-mounted rolls (e. g., twoupperxrolls) l are associated to a second brace. "The hyperboloidalrolls of one brace have spaced parallel axesywhile'the hyper-";b'olo'ids of'the other brace-have either a'common axis or spacedparallel axes; so disposed that then-e0: the;.rolisi;'-oi-.;eachpairrbeingwdisposed w-ith-itheir trolls" of one'pair of matinghyperboloids= of the -setmake contact with-"each other-along age-n- 1rotationkwiththeshaf t '8'! about itsaxis. nknother wbraceoi-hyperboloidal rollsJQEB and: 9631s simielarlyz mounted .on shaft- 85.Theaupperehyper- -:bo-loidaL--rolls' '931t.- ands-9 b tarerretatableabout ."form. a brace; similarly,- the o-ther two*hke-gzs'zsthe shafts9'! and-98 respectivelywhose axes are :mounted rolls (e.-g., twolowerrolls) constitute .-.carri ed:1n spaced:p'arallehrelation by athecas-tin-=99"so. that the: anglerbetween;thetaxesofrrotation :of the: pair 83A,3B=is the sameias ithat between ;Jthe.- axes of :rotation: of .,=.thepair: ':-9.4A-:-. andiBAB,

:-.xgorge.:-circles in substantially; opposed; relation. Theaupper..rollsi- 95A and-96A: are rotatable. about theyshafts': Hi0 .and :I ll irespectiveiywwh-ich; are -.-=.carried; by the .casting .I .82 with-themaxes in parxboloids make contact with each other. "It will .35-.-allel;;spaced.relationesothatxthe:gorgezcircless-of "-be'readilyunderstood that if the axes of both i braces areea ch spacedand-parallel, the plane determined by the parallel axes of one bracewill *beparallelto the plane determined by the-par- -.the; pair xefiAfiBzandaof themairri fifiA-mandilfiB arezin substantiallyppposedrelati'on.

The castings 99 and H32 are carried byzm'ountiigingimeans correspondingto the mountingmeans a11e1 axes of the other brace. In short,-adjacentuionfor: the-castings 61-- an-d-i 65 rofil-the embodiment pairsof matinghy-perboloids of-likeiunetion are associated in sets; eachsetcomprises two braces, and each-brace comprises two like-moun-ted rolls:

' the axes of at least one braceare spaced and -'--=par'a1lel;"theaxes-of the-otherbrace-are'prefere eandare+heldinwplace=endwise-ofetherodtbyjzhe -ably coincident but may be spaced and parallel; and thegenerator of contact of one mating pair '-is parallel to the generatorof contact of the other The rollsconstituting-one. of the@showniirrEigs. 9 .and 10,-and.the-elementsthereof n aredndicated-bydike:reference characters. Thus, -.-the:@castings;-9 Brand l02- are boredto; receive-:the :rod: 7 I. forrf-r-ee rotation .aboutthe. axis 0f rod 1l .-.-collars; orzsnap rings: 12. One end .ofzthe" rod 1 I isslidahly-heldwin the-vertical; groove 13in; .the .post While :the otherend of. the :rodis-similarly eonstrainedby, the groove -15 in thebarl 6.?The braces can be carried by common mounting ':means fora urgingtheupperrolls-93A,-;94A,;.95A

- means therefor so as to maintain the-gorge cir- :c1es thereof insubstantially opposed relation .to '"thegorge circles of the respectiverolls of. the ='other brace for frictional contact-with roving therebytoward the rolls: of the other bracewi'th 1 substantially equaldistribution of load between C3 each of the pairs of'hyperboloid'al'rolls. (When a-surface is generated by the motion of ,a straight linegthat line is ca11ed*the generator, and each position ofthe linein thesurface is called a-gem and 95A towarclthe lower rolls 93B, 94B, 95B;and

AitB-is: also the same as that shown in'Figs. 9 and 10 includingtherod-8i] terminating in the-ball 8! which-rests in arslight depressionin-zatboss 82 on-casting- 99,-xthe lower endof the rod-:80 beingprovided with the fulcrum-'83 for-the-iever 8 itpivotallyattachedto thebase at v85. The relative distribution. of the 'load'c'orresponds withthat described more fullyhereinabovein connection with .theuembodimentshown in Figs. 9 and 10.

" Another group. consisting :of one setz'oftwo 7 adjacent pairs ofhyperboloidal' rolls arranged'in ztandemi-with another settof two.adjacent pairs wof 'hyperboloidal rolls is 'shown. in Figs. 11*and'12aerator. A hyperboloidalsurfaceisproduced by. vC5 which:duplicatesrthegroup just described. "In

ithe rotation of a straight'line, i; e., the" generator,

about a second *non parall'el v non-intersecting straight line. calledthe axis. "When two hyper- :boloids are .in proper'mating.contact; thatconthis-group, :the ":lower ihyperboloidali' rolls 1 03B and- HMB aremounted for coi-axial rotation with the:shaftiflLzand: the lowerhyperboloidal" rolls 10513- and 10613 are :mounted for co-axialrotationtact is along a straight line which isaxgenerator. to with shaft 86. Theu per rolls |03A' andI*lMA common to: both hyperboloids.)

-In Figs. lland 12, the aboveementioned prin .ciples are embodied, in analternative. construc- ,tion embodying my: invention. lialthissembodi-.zarer'mountedi for rotation 4 about shafts 0! and14-08wrespectivelywhich are carried withitheiraxes wimparal-lel spacedrelation by the castingil'OSJy-and .the :upperrolls 15A: and-106A aremounted for ..ment, the numberof shaftsextending along .the75;:rota-tion caboutrzshafts Hi] and: HI respectively which are carriedwith their axes in parallel spaced relation by the casting I I2. Themounting means for the castings I69 and H2 is a duplication of thatprovided for castings 99 and H12 and the parts thereof are indicated bylike reference characters. These structures are repeated throughout theframe.

As in the embodiment shown in Figs. 9 and 10, the roving 2U first passesbetween the feed rolls, e. g., 33A, 93B and thence to the draftingrolls, in this case 95A, 9513. The roving then passes through the eye l3and the traveler [5 to the spindle M for reception thereby while it issubjected to true spinning as hereinabove described.

In comparing the embodiment shown in Figs. 9 and 10 with that shown inFigs. 11 and 12, it

will be seen that they both comprise two kinds of braces ofhyperboloi-dal rolls in which the two rolls of one brace are mounted onparallel spaced shafts and the two rolls of the other brace are mountedon co-axial shafts. Thus, in Figs. 9 and 10, the hyperboloidal rolls ofeach driving brace (lower rolls) are mounted on spaced parallel shafts,while the hyperboloidal rolls of each idling brace (upper rolls) areco-axial. In Figs. 11 and 12, however, the reverse is true, viz., therolls of the lower braces are co-axial while the rolls of the upperbraces have spaced parallel axes. It will be immediately recognized thatit is possible to construct the spinning frame so that it is a hybridbetween that shown in Figs. 9 and 10 on the one hand, and that shown inFigs. 11 and 12 on the other. It will be obvious that matters can be soarranged that the rolls of both upper and lower braces can be mounted onspaced parallel shafts by using a combination of the upper structure ofFigs. 11 and 12 with the dual-shafts of Figs. 9 and 10.

The structure shown in Figs. 9 and 10 and likewise that shown in Figs.11 and 12 disclose an association of braces of rolls of differentfunction on a common rod or shaft, for instance, the rod H in Fig. 9, bymeans of which the drafting brace of rolls 59A-68A and the feeding braceof rolls 55A-56A are located on the frame in proper relationship totheir respective mating hyperboloids. This arrangement has structurallyadvantages which are applicable not only to hyperboloidal spinning butalso to spinning frames employing cylindrical rolls. It will be seenthat base of the machine is provided with a grooved post M and a groovedbar is which together serve to locate all four upper rolls for twoadjacent spindles. In conventional frame structures, however, it isnecessary to employ twice as many locating means for the same duty.While the upper hyperboloids of a brace of rolls of Fig. 9 are co-axialand those of Fig. 11 are mounted on spaced parallel axes, neverthelessthey have in common the feature that a brace of hyperboloids of onefunction (e. g., feeding) and a brace of hyperboloids of anotherfunction (drafting) are associated on a common member which locates bothbraces with respect to the frame and which permits each brace to rockindependently about the axis of the common member.

Moreover, this common member serves as a load driving arrangement forthe upper rolls, that is to say, only the lower rolls are power drivenand the upper rolls are driven by friction from the i lower rolls. In myexperiments, 1' haveused this same arrangement. However, it must beborne in mind that the conditions obtaining in hyperboioidal rollsdiffer substantially from those obtaining in cylindrical rolls so thatwhereas, in the case of cylindrical rolls, satisfactory drive of theupper rolls is obtained by frictional drive from the lower rolls,nevertheless the altered circumstances may make it desirable to drivethe upper hyperboloidal rolls mechanically so as to insure more positiveequalization of the speed of the upper rolls with that of the lowerrolls. By a simple modification of the arrangement shown in 9 and 10, itis feasible to drive the brace of upper feed rolls and the brace ofupper draft rolls from one of the shafts of the lower feed rolls and oneof the shafts of the lower draft rolls respectively as shown in Figs.13, 14 and 15.

In Figs. 13, 14 and 15, the shafts 43, it, 45 and .5 are power driven.and are the same shafts which are indicated like reference characters inFigs. 9 and 10 and which carr for rotation therewith the lowerhyperboloioial rolls 55B, 55B, 59B and 83. Also as in Figs. 9 and 10,the brace of upper feed rolls 55A, 55A. is mounted on the shaft 63 whichis rotatably mounted in the casting E? that is rockable about the shaft1!. For the sake of clarity, only the upper roll 50A of the brace ofupper draft rolls 55A and 59A is shown in Fig. 3.3, the brace beingmounted on the shaft E55 which is rotatably carried by the casting 55that likewise is rockable about the shaft H. In Fig. 15, thehyperboloidal roll 55A shown as comprising the surfacing layer 515 offibrous composition which is held between the collars Hi5 and ii? forrotation with. the annular core HS that is keyed to the shaft 63 forrotation therewith. The roll 56A is of similar construction, and thesame applies to all hyperboloidal rolls that are shown in Figs. 13, letand 15.

In order that the upper hyperboloidal rolls 55A and 5th may bepositively driven, the collar ill has a gear H9 machined integrallytherewith which meshes with the gear I23) that rotates integrally withthe roll 55B and with the driven shaft G5. The gears lit, we arehyperboloidal so that when the shaft 35 and the hyperboloidal roll 55Bare rotated, the hyperboloidal roll 55A and the shaft 63 are rotated inthe opposite irection and at the same speed. Since the roll 56A likewiseis keyed to the shaft 83, the roll 58A is positively driven so that itsperipheral speed will correspond with that of its mating roll 55B.Similarly, the brace of rolls 59A and 69A (roll 60A only being shown inFig. 13) is positively driven from the driven shaft 63 by correspondinghyperboloidal gears of which only one gear, namely, the gear Mil, isshown in Fig. 13.

Referring to Fig. 16, the means for positively driving the upper feedrolls and upper draft rolls is analogous to that described above inconnection with Figs. 13, 14 and 15. In Fig. 16, the upper rolls e3A,9M5, 35A and 3th; the lower rolls 33B, 94B, B, and 563; the shafts 86and 87; the castings 99 and M2: and the shaft 7! are the same as theparts bearing the same reference characters shown in Figs. 11 and 12. Inthis embodiment, the upper rolls 93A, .t lA, 95A and 96A have the gears522A, 123A, 424A and I25A respectively that are mounted for rotationtherewith and that are driven by the gears 22B, i233, I243 and [253-that are mounted for rotation with the lower roils 93B, 95B, 95B and965. It is apparent, therefore, that each of the upper '17 hyperboloidalfeed rollsttA and 94A is positively driven from the driven shaft 81,while each of the-upper hyperboloidal draft rolls 95A and 95A ispositively driven from thedriven shaft 36:

In the design of the gearing for the embodiment shown in. Figs. 13 to16, gearing having teeth with long addenda permits the movements of theupper roll braces relatively to the rolls of the lower braces in themanner and for thepurposes as hereinabove described while maintainingthepositive drive for the upperrolls. While hyperboloidal gears arepreferred, the more commonly used helical gears approximate theshape ofhyperboloidal gears sufficiently closely to permit the use of helicalgears.

In conventional systems using cylindrical rolls, it is usual to employlower or driven rolls of steel suitably fluted and upper or idling rollsof rubber both for the feeding and for the drafting. I have used thesame combination of materials for my experiments on hyperboloidalspinning, but my invention is not to be" construed as being in any wayrestricted to such materials. For example, I have succeeded in obtainingsatisfactory results by using steel for both the upper and lower rollsof the drafting pairof hyperboloids, provided that the working surfacesof such hard rolls are sutiably roughtened, e. g, by schreinering. Infact, hard surfaced rolls for both upper and lower rolls of thedrafting.

pair 'of hyperboloids appear to be much more stable in their action thanrolls of softer material like rubber or rubber-like plastics. In lieu ofroughening the surface of the roll material itself in order to provide asurface having greater friction with roving passed therebetween, whenthe roll material employed is steel or is any other material of suchhardness as to maintain the hyperboloidal drafting rolls out-of-contactwith each other during drafting, a similar effect can be-obtained bysurfacing the roll material with a thin layer of softer material such asrubber or a plastic. When the roll material'is hard, such as roughenedsteel or such as steelcoated with-athin layer of a softer material suchas rubher or plastic, I prefer to employ hyperboloidal rolls which arerelatively narrow as compared with the draft rolls used in conventionalsystems or as compared with the practice of myinventionusing-hyperboloidal rolls composed of a soft material such asrubber.

While apparatus according to the embodiments of my invention shown inFigs. 9 to 16 comprises weighting means specially provided for imposingload on the upper braces of feed rolls and draft rolls, it is not in allcases necessary to employ such special weighting or other load imposingmeans. Thus, in the constructions shown, the weight of the upper rollbraces and the mounting means therefor, e. g., in Fig. 9 the braces ofrolls '55A56A-and 49A65A, the castings 67 and 69, and the rod H, may besufiicient to provide the necessary load on roving passing between theupper and lower hyperboloids of the mating roll pairs. This isespecially the case when the hyperboloidal rolls present a surface suchas rubber that produces relatively high friction with the roving andwhen the upper rolls, as well as the lower rolls are positively driven.weight ofupper roll braces and the mounting means therefor constituteloading means for urging the rolls of the upper braces toward the.respective mating rolls of the. lower braces. However, the employmentof loading means effec- In'such cases it is apparent that thetivezinaccordance with, the constructions shown in Figs. 9 and 16 is preferablein'that the. amount of load. may be more readily adjusted to. meetvarying requirements, while atthesame time avoiding the. necessity formanufacturing the upper hyperboloids and the mounting means therefor topredetermined weight requirements.

The diameter of a hyperboloidal surface of revolution isa minimum at thegorge circle and increases according to a parabolic law as one goes awayfrom the gorge circle in a direction parallel to the axis. The rateofchange of diameter is very small at first and increases more rapidly asthe distance from the gorge circle increases, in

accordance with said parabolic law. If theangle of the hyperboloids isnot too large, then, for small distances on either side of thegorge-circle, the change in diameter of each hyperboloid is very small.Hence, as is well known in the spinning-art, I can cause the roving tooscillate over this small distance so as to distribute the wear on therolls. Alternatively, I can oscillate one of the hyperboloids of thepairs of hyperboloidal rolls along a generator thereof over a shortdistance on either side of its gorge circle without appreciablyaffecting the rate of feed or the rate of draft. Bythus oscillating oneof the hyperboloids of each pair over a short distance on each side ofits gorge circle, I can distribute the wear on the rolls, to a, materialextent. Thisv oscillation can be imparted, for example, by oscillatingin the proper direction either the shafts on which the lower rolls aremounted or the shaft on which the upper rolls are mounted. The rate ofoscillation is slow relatively to the feed.

While this invention has been described, in connection with certainspecific embodiments and examples, it is to be understood that this hasbeen done for purposes of illustration and that this invention comprisesfeatures, which-are preferablyavailed of in combination. for thepurposesherein stated but which may be availed of separately and thatthe practice of this invention may be varied within the scope thereof asgoverened by the language of the following claims as construed in thelight of the foregoing description.

I claim:

1. A method of drafting a stretch of roving which comprises the stepofsubjecting said roving to alongdraft of at least about 4to 1 bydrawingsaid roving across a stretch not exceeding substantiallythreefiber lengths while subjecting said roving. in the region of minorlength adjacentv the end. of said stretch toward which said rovingisdrawn to a false twist in excess of that permitting substantialdrafting of the fibers in saidregionsaid false-twist in excess of thatpermitting substantial drafting being localized in said region by saidlong draft and the fibers of said roving being drawn into said region offalse twist wherein said false twist is in excess of that permittingsubstantial drafting, from the balance of said stretch-of greater lengthmerging therewith: in which there is diminishing-twist away from saidregion permitting said long drafting of said roving.

2. A method of drafting a'stretch of roving comprising the stepaccording to claim 1 and wherein; the-roving immediately prior to beingfedinto said stretch is subjected to a false twist in the samedirection. as the false twistto which said; roving is subjected in saidregion adjacent the. end of said stretch.

' 3: ii'methodfof draftinga' stretch of roving 19 comprising the step ofclaim 1 wherein said long draft is at least to 1.

4. In apparatus for drafting roving, a pair of hyperboloidal rollscomprising an upper roll and a lower roll, an adjacent pair ofhyperboloidal rolls likewise comprising an upper roll and a lower roll,a common shaft upon which both upper rolls of said pairs are mounted indumbbell fashion, and a pair of spaced parallel shafts on one of whichone of said lower rolls is mounted and on the other of which the otherof said lower rolls is mounted, the spacing between said parallel shaftsand. the angle made by said common shaft with said parallel shafts beingsuch that,

common shaft, and means permitting movement of said support and therolls carried thereby .for urging same toward said rolls carried by saidspaced parallel shafts with substantially-equal distribution of loadbetween each of said pairs of rolls while maintaining the gorge circlesof said pairs of rolls in substantially opposed relation.

6. Apparatus for drafting roving comprising two adjacent pairs ofhyperboloidal rolls, the

rolls of each pair being rotatablymounted for rotation about axesdisposed at an angle which is essentially the same for each pair ofrolls, the axis of rotation of one roll of one of said pairs beingparallel to and spaced from the axis of rotation of one roll of theother pair, and the remaining rolls of said pairs being rotatable abouta common axis disposed at said angle with respect to said spacedparallel axes.

7. Apparatus for drafting roving according to claim 6 wherein said rollsrotatable about a common axis are carried by a common shaft having asupport therefor located between said rolls.

8. Apparatus for drafting roving according to claim 6 wherein said rollsrotatable about spaced parallel axes are carried by spaced parallelrotatable driven shafts and are mounted for rotation with said shafts,and which comprises a common shaft for carrying said rolls rotatableabout a common axis, a support for said common shaft located between thesaid rolls carried thereby, means for mounting said support adapted toafford bodily and rocking movements thereof for permitting variations inthe spacing of the rolls of said respective pairs while maintaining thegorge circles of the rolls of each of said pairs in substantiallyopposed relation, and means for urging said support toward said parallelshafts to maintain roving in frictional contact with and between saidrolls carried by said common shaft and said rolls carried by said spacedparallel shafts.

9. Apparatus for drafting roving according to claim 6 wherein said rollsof said pairs which are rotatable about spaced parallel axes are carriedby a common support located between said rolls.

10. Apparatus for drafting roving according to claim 6 wherein saidrolls rotatable about a common axis are mounted on a common driven shaftfor rotation therewith, and which comprises a common support for saidrolls rotatable about said spaced parallel axes, means for mounting saidsupport adapted to afford bodily and rocking movements thereof forpermitting variations in the spacing of therolls of said respectivepairs while maintaining the gorge circles of the rolls of each of saidpairs in substantially opposed relation, and means for urging saidsupport and the rolls carried thereby toward said rolls carried by saidcommon shaft to maintain roving in frictional contact with and betweensaid rolls carried by said support and said rolls carried by said commonshaft.

11. In apparatus for drafting roving, two adjacent pairs ofhyperboloidal rolls, one roll of each pair being mounted on a commonshaft and the remaining rolls of said pairs being carried by a commonsupport for rotation about spaced parallel axes, and means permittingmovement of said common support and the rolls carried thereby for urgingsame toward said rolls carried by said common shaft with substantiallyequal distribution of load between each of said pairs of rolls whilemaintaining the gorge circles of said pairs of rolls in substantiallyopposed relation.

12. Apparatus for drafting roving which comprises two adjacent pairs ofmating rotatably mounted hyperboloidal rolls, one roll of one of saidpairs and one roll of the other of said pairs constituting a brace ofrolls wherein the axis of rotation of one of said rolls is parallel toand spaced from the axis of rotation of the other roll, and theremaining rolls of said pairs constituting a second brace of rolls theaxis of rotation of each I of which makes the same angle with the axisof rotation of each of the rolls of the other brace, and common mountingmeans for the rolls of one of said braces of rolls adapted to maintainthe gorge circles of the rolls of said brace in substantially opposedrelation with the gorge circles of the rolls constituting said otherbrace for frictional contact with roving therebetween.

13. Apparatus for drafting roving according to claim 12 which comprisestwo additional adjacent pairs of hyperboloidal rolls according to thosedefined in claim 12 and arranged in tandem therewith.

14. Apparatus for drafting roving which comprises two adjacent pairs ofmating rotatably mounted hyperboloidal rolls, one roll of one of saidpairs and one roll ofthe other of said pairs constituting a first braceof rolls wherein the axis of rotation of one of said rolls is parallelto and spaced from the axis of rotation of the other roll, and theremaining rolls of said pairs of rolls constituting a second brace ofrolls the axis of rotation of each of whichmakes the same angle with theaxis of rotation of each of the rolls in said first brace of rolls,common mounting means for carrying one of said braces of rolls, andmeans permitting movement of said common mounting means and said braceof rolls carried thereby for urging same toward the rolls constitutingsaid other brace with substantially equal distribution of load betweeneach of said pairs of rolls.

15. Apparatus for drafting roving which comprises two adjaoent pairs ofmatiw hyperboloidal rolls, each roll rotatably mounted about its axis insubstantially opposed relation to its mate at the gorge circles thereof,one roll of one of said pairs and one rollof the other of said pairsconstituting a first brace of rolls wherein the axis of rotation of oneof said rolls is parallel to and spaced from the axis of rotation of theother roll, and the remaining rolls of said pairs of rolls constitutinga second brace of rolls, said braces of rolls being arranged with thegenerator of contact of one mating roll pair parallel to the generatorof contact of the other mating roll pair and with the axes of rotationof the rolls of one brace fixed, a common support for the rolls of theother brace adapted to fixedly determine the axes of rotation of therolls in said brace rela-v tively to said support, mounting means forsaid support which allows rocking movements of said support about anaxis substantially parallel to the direction of draft and substantiallyequally distant from the locus of the opposed gorge circles of therespective pairs and which permits movement of said support and thebrace of rolls carried thereby for urging same toward the other brace ofrolls.

, 16. Apparatus for drafting roving which comprises a first set of twoadjacent pairs of mating rotatably mounted hyperboloidal rolls, a secondset of two adjacent pairs of mating rotatably mounted hyperboloidalrolls arranged with each pair thereof in tandem to each pairrespectively of said first set for sequential action on roving passedtherebetween, in each set there being one roll of one pair disposed withits axis of rotation parallel to and spaced from the axis of rotation ofone roll of the other pair and each of the remaining rolls of said pairsbeing rotatable about an axis disposed at the same angle with respect tosaid spaced parallel axes, four rolls of said first and second setshaving their axes of rotation disposed substantially in one plane andconstituting a first group and the other four rolls of said first andsecond sets having their axes of rotation disposed substantially inanother plane in parallel spaced relation to said first plane andconstituting the second group, common carriage means for carrying therolls of one of said groups,

and means for urging said common carriage means and the rolls carriedthereby toward the rolls of the other group while maintaining the gorgecircles of each pair of rolls in substantially opposed relation.

17. Apparatus for drafting roving according to claim 16 wherein thedistance from the nip between the pairs of hyperboloidal rolls in saidsecond set to the nip between the hyperboloidal rolls of the first setis of the order of magnitude not greater than three fiber lengths andwherein said first and second sets are operatively arranged forsubjecting roving passing from the hyperboloidal rolls of said first setto the hyperboloidal rolls of said second set to a long draft in thestretch between the aforesaid nips, the rolls of said second set beingadapted to impart twist to roving in the region of the immediateneighborhood of the nip therebetween sufficient to prevent substantialdrawing of the fibers in said region while permitting longdraft of thefibers in the portion of said stretch more adjacent the nip between therolls of said first set wherein less twist occurs.

18. Apparatus for drafting roving which comprises two adjacent pairs ofmating rotatably mounted hyperboloidal rolls, one roll of one of saidpairs and one roll of the other of said pairs constituting a first braceof rolls wherein the axis of rotation of one of said rolls is parallelto and spaced from the axis of rotation of the other roll, and theremaining rolls of said pairs constituting a second brace of rolls theaxis of rotation of each of which makes the same angle with the axis ofrotation of each of the rolls of the other brace, a shaft equally spacedfrom the locus of the opposed gorge circles of the respective pairswhose longitudinal axis is disposed normally to the bisector of saidangle in a plane susbtantially parallel to the plane of the lines ofcontact of said pairs of rolls, a support carried by said shaft which isrockable about said axisof said shaft in fixed relation to thelongitudinal extent of said shaft, means for rotatably carrying therolls of one of said braces of rolls by said support with the gorgecircles thereof substantially opposed respectively to the gorge circlesof the rolls of the other brace, means for mounting said shaft to permitmovement thereof limited to non-axial movement normal to said plane, andmeans for imposing force applied in a direction substantiallyintersecting the axis of said shaft and effective for urging the braceof rolls carried by said support toward the other brace of rolls withsubstantially equal distribution of load between the rolls of said bracecarried by said support.

19. Apparatus for drafting roving according to claim 18 wherein there isa second set of two adjacent pairs of hyperboloidal rolls arranged intandem with the first set of hyperboloidal rolls, said second set ofadjacent pairs of hyperboloidal rolls being arranged in braces asdefined for the aforesaid braces of said first set, the rolls of one ofthe braces of said second set being carried by a second support "whichalso is carried by said shaft and which is rockable about thelongitudinal axis of said shaft in fixed relation to the longitudinalextent of said shaft, and wherein said means for imposing force iseffective to urge the rolls of the braces of said first and second setscarried by said supports therefor toward the other rolls of the pairs insaid sets with equal distribution of load between the pairs of each setand with predetermined distribution of load between the respective sets.

BENJAMIN LIEBOWITZ.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 32,923 Partridge July 30, 18611,772,109 Quaas Aug. 5, 1930 1,922,949 Harris Aug. 15, 1933 2,246,474Stahlecker June 17, 1941 FOREIGN PATENTS Number Country Date 28,325Great Britain July 2, 1908 275,875 Italy July 5, 1930 324,540 GreatBritain Jan. 30, 1930 502,216 Germany July 11, 1930 588,401 Germany Nov.18, 1933 769,512 France Aug. 28, 1934

